Piping systems are used in structures to supply liquids and gasses and to-carry sewage and other wastes away. Common household piping or plumbing systems include water supply piping, drain piping, and possibly gas piping. Water supply pipes carry water from a water supply pipe to plumbing fixtures such as sinks, baths and showers, toilets, sprinkler systems, spigots, and the like. Drain piping carries human wastes, ground garbage from disposers, and waste water to sewers or septic tanks. Gas piping, if present, carries fuel gases such as natural gas or propane gas to appliances such as furnaces, ranges, gas fireplaces, and the like. A particularly necessary quality of all types of piping is integrity of the pipes and joints such that the liquids or gases carried do not leak.
In order to ensure that a piping system does not leak, pressure testing is often conducted and may be required by some local codes. Plumbing is preferably installed, tested, and joints repaired, as needed, prior to closing access to the piping and joints by the installation of wallboards. Testing often involves pressurizing the piping system with compressed air, or alternatively filling it with water, and detecting any leaks. Testing is usually done before any fixtures, appliances, or the like have been connected to the piping system.
Plastics, such as PVC or polyvinyl chloride and others, are used in many types of plumbing, including waste plumbing. It is common practice, during testing, to install removable test plugs or caps on pipe stubs to which fixtures, such as toilets, will be subsequently connected. After testing is completed, the caps are removed. The test caps need to be sealed in place such that they do not leak during testing. When the test caps are no longer needed, they need to be removed in such a manner that the test cap is not lost in the waste plumbing, such that the remaining plumbing is not damaged by removal of the test cap, and such that no remaining parts of the test cap assembly interfere with the fixture to be installed. Additional features which would be desirable in such a test cap include the capability of conveniently connecting a source of pressurized fluid to the cap and resealable structure for conveniently testing that the piping system is pressurized.
The present invention provides a knock-out pressure test cap with a break-away nipple plug which provides increased functionality in such a test cap. The cap includes a cylindrical mounting collar or wall sized to be sealingly positioned within a pipe. A mounting shoulder on the mounting wall limits the depth of insertion of the cap into the pipe. A closure disc closes the space surrounded by the mounting wall and is connected to the mounting wall by a weakened break line to enable separation of the closure disc from the mounting wall subsequent to testing.
The closure disc has a peripheral rim including an inwardly projecting inner or connection rim portion which connects the closure disc to the mounting wall by way of the break line. The peripheral rim also has an outwardly projecting outer or impact rim portion which is circumferentially aligned with the inner rim portion. Impacts, such as by a hammer, are transferred through the rim to the break line, causing it to fail or rupture such that impacts around the outer rim portion cause the closure disc to be separated from the mounting wall. The outer diameter of the inner rim is slightly greater than the inner diameter of the mounting wall so that the closure disc, once separated, cannot be knocked into the pipe and made difficult to recover.
A nipple with a removable nipple plug is formed on the closure disc. The nipple facilitates grasping of the cap with a user""s fingers or with a wrench while applying cement to the cap mounting collar or insertion of the cap within a pipe to be sealed. The nipple plug is connected to the outer end of the nipple by a weakened break line, to facilitate separation of the nipple plug from the nipple. When the nipple plug is removed, a hose may be connected to the nipple to supply air or water to the pipe through the cap to pressurize the plumbing system for testing.
Various objects and advantages of this invention will become apparent from the following description taken in relation to the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention.
The drawings constitute a part of this specification, include exemplary embodiments of the present invention, and illustrate various objects and features thereof.